Contralateral Approach to Bilateral Middle Cerebral Artery Aneurysms: Comparative Study, Angiographic Analysis, and Surgical Results

BACKGROUND

Bilateral aneurysms located between the 2 middle cerebral artery (MCA) bifurcations may be approachable through a single unilateral approach.

OBJECTIVE

To identify anatomic parameters based on imaging that would favor a contralateral approach.

METHODS

From January 1998 to December 2013, we retrospectively identified 173 patients with bilateral intracranial aneurysms. Fifty-one patients had bilateral MCA aneurysms. A total of 38 patients underwent a single craniotomy with a contralateral microsurgical approach (group 1 or contralateral group) and 13 patients underwent bilateral craniotomies (group 2 or bilateral group). For both groups, we analyzed aneurysm characteristics, morphology, size, projections, and distance to the contralateral corridor, as well as surgical time, outcome, and postoperative complications.

RESULTS

All aneurysms approached contralaterally were unruptured and without wall calcifications. Of the contralaterally approached aneurysms, 97% were smaller than 14 mm. The median length of the contralateral A1 was 13.2 mm (range: 6-19.8 mm) and the median length of the contralateral M1 was 14.2 mm (range: 4.6-21 mm). The contralateral group had a good postoperative outcome (modified Rankin Scale 0-3) in 80% of ruptured cases and 86% of unruptured cases. The median surgical time was 120 minutes (range: 75-255 minutes), 43% shorter than the bilateral group.

CONCLUSION

The contralateral approach for bilateral MCA aneurysms in selected patients is feasible in experienced hands, with acceptable morbidity and mortality. The contralateral approach requires a meticulous preoperative analysis of the characteristics of the aneurysms to be clipped and of the anatomic constraints of the microsurgical operative corridor.

ABBREVIATIONS

A1, anterior cerebral artery proximal segmentbMCA, bilateral middle cerebral arteryCTA, computed tomographic angiographyHH, Hunt-Hess scaleIA, intracranial aneurysmsICA, internal carotid arteryICAbif, internal carotid artery bifurcationMCA, middle cerebral arteryM1, middle cerebral artery proximal segmentmRS, modified Rankin ScaleSAH, subarachnoid hemorrhage.

Endovascular and Surgical Treatment of Unruptured MCA Aneurysms: Meta-Analysis and Review of the Literature

Introduction. The best treatment for unruptured middle cerebral artery (MCA) aneurysms is unclear. We perform a meta-analysis of recent publications to evaluate the results of unruptured MCA aneurysms treated with surgical clipping and endovascular coiling. Methods. A PubMed search for articles published between January 2004 and November 2013 was performed. The R statistical software package was used to create a random effects model for each desired incidence rate. Cochran's Q test was used to evaluate possible heterogeneity among the rates observed in each study. Results. A total of 1891 unruptured MCA aneurysms, 1052 clipped and 839 coiled, were included for analysis. The complete occlusion rate at 6–9 months mean follow-up was 95.5% in the clipped group and 67.8% in the coiled group (P < 0.05). The periprocedural thromboembolism rate in the clipping group was 1.8% compared with 10.7% in the aneurysms treated by coiling (P < 0.05). The recanalization rate was 0% for clipping and 14.3% for coiling (P = 0.05). Modified Rankin scores of 0–2 were obtained in 98.9% of clipped patients compared to 95.5% of coiled (NS). Conclusions. This review weakly supports clipping as the preferred treatment of unruptured MCA aneurysms. Clinical outcomes did not differ significantly between the two groups.